Nanoporous activated carbon fibers (Busofit^TM, BACF) showed effective adsorption of carbon tetrachloride (CTC) vapors. About 2.50 mmol × g⁻¹ of chlorine, in the form of trichloromethyl and chlorine groups, can be grafted onto BACF surface by thermal decomposition of CTC at 450 °C. To obtain solid acids, this chlorinated BACF, the brominated and pristine BACFs, taken for comparison, were subjected to progressive sulfidation, hydrolysis and oxidation reactions for grafting sulfonic groups. By this wet route, sulfonic groups can substitute only 1.1–1.4 mmol × g⁻¹ of the grafted chlorine groups. Nevertheless, solid acids obtained in this way have high catalytic performance in the 2-propanol dehydration to propene. For these catalysts, in the range from 180 to 220°C, a 100% alcohol conversion with 100% selectivity to propene could be reached. Thermoprogrammed desorption and thermal analysis revealed that the pyrolytic chlorination triggers the highest thermal stability of grafted sulfonic groups, and, they can repeatedly act in the dehydration reaction.

The present study is objected to develop an analytical remote optical diagnostics of the functionalized carbons surface. Carbon composites with up to 1 mmol g−1 of irreversibly adsorbed bromine were produced by the room temperature plasma treatment of an activated carbon fabric (ACF) derived from polyacrylonitrile textile. The brominated ACF (BrACF) was studied by elastic optical scattering indicatrix analysis at wavelength 532 nm. The obtained data were interpreted within results of the thermogravimetric analysis, X-ray photoelectron spectroscopy and temperature programmed desorption mass spectrometry. The bromination dramatically reduces the microporosity producing practically non-porous material, while the incorporated into the micropores bromine induces the dielectric and structural impact on surface polarizability and conductivity due to the charging effect. We have found that the elastic optical scattering in proper solid angles in the forward and the backward hemispheres is sensitive to the kind of the bromine bonding, e.g., physical adsorption or chemisorption, and the bromination level, respectively, that can be utilized for the express remote fabrication control of the nanoscale carbons with given interfaces.

Polyacrylonitrile carbon fibers (PAN CFs) were sulfurated at high temperatures and then oxidized with an H₂O₂ solution. Thermal and chemical analysis showed high thermal stability and the sulfur content up to 4 mmol g⁻¹. From the microwave absorption studies, the voltage standing wave ratio and the attenuation through one adsorbent layer decrease almost linearly with increasing frequency. The reflection coefficient equals 0.79 ± 0.017 and 0.473 ± 0.02 at 10 and 30 GHz. "Transparency windows" with a bandwidth of about 300 MHz are observed at 30 and 36 GHz. The 1000 times attenuation of the signal power is found at 30 GHz.

Activated carbon fibers originated from viscose was brominated in the dibromine solution. An active surface precursor with 1.0 mmol of bromine per gram of carbon fibers was obtained. The bromine groups are capable for a further replacement, e.g. for amines residues. The thermochemical properties of the synthesized samples were studied. The rules of the surface layer bromination were discussed within the results of the thermal and chemical analysis. Two types of bromine groups on the carbon fiber surface were determined by the thermal desorption. These groups were associated with different centers situated on the accessible surface or placed in tight nanoscale pores. The reason of such distribution was the bromination that producing groups which binding strength varies and the effect of configuration factor. This factor limits the thermal desorption of various gaseous molecules which were formed and released during the thermal decomposition of grafted functionalities and sorbed by the samples with small nanosized pores. The use of the precursor route shows that the interface covered with from 0.62 to 0.95 mmol/g of the residual amine functional groups can be prepared.